Comparative religion is the scholarly study of the world's religions set side by side, comparing their beliefs, practices, texts, and institutions in order to understand each more clearly and to discern what, if anything, they genuinely share. It emerged as a distinct discipline in the nineteenth century out of the new philology and the growing European encounter with the sacred texts of Asia; Max Muller, who edited the vast Sacred Books of the East series, is often regarded as a founder, and is remembered for the maxim, adapted from Goethe, that "he who knows one, knows none", the claim that a single religion cannot be understood in isolation.
The field developed the tools of typology and cross-cultural comparison, seeking recurring categories, myth, ritual, sacrifice, prophecy, mysticism, scripture, across traditions. Its history is not without serious criticism: scholars have shown how the very category of "religion," and the neat parceling of the world into a set of discrete "world religions," is itself partly a modern European construction that can distort the traditions it classifies. Contemporary practitioners are correspondingly careful to attend to difference as much as similarity and to the historical and political contexts of comparison. As an academic discipline (overlapping with "religious studies"), it is distinguished by its commitment to studying religions descriptively and comparatively, from a standpoint that neither presumes nor denies the truth of any of them.